| This paper intends to analyze the rock samples from QK2,combined with Regional Geological Survey report of Tuco area.Compared with previous studies of sedimentary evolutionary stages and mechanisms of the Late Triassic basin in Qiangtang,especially the research on sediments of QK2,analyze sedimentary section of Tumengara group,Triassic,in Qiangtang basin.And further,conclude sedimentary characteristics,sequence evolution,and Paleogeographic features of the area.Set up stratigraphic framework and age stratigraphic framework of this period,looking forward to help improve the level of basic geological research and exploration in the field.The author details lithology,rock composition and sedimentary structures and faults of QK2 core in the wild.Combined with structural characteristics,stratigraphy and characteristics of Sedimentary system of the region and minerals and elements characteristic,analyze the sedimentary facies and discuss about depositional environment.The geological characteristics and stratigraphic characteristics of the study area are showed that QK2 core part of the Upper Triassic Tumengela group;This paper intends to analysis QK2 hole lithology,rock composition,sedimentary structure characteristics,combined with knowledge of sequence stratigraphy,sedimentology,sedimentary petrology,distinguishing 2 types of sedimentary facies:Delta facies and Shore Zone facies,2 types of sedimentary subfacies:delta-front subfacies and Shore face subfacies,8 types of microfacies:Underwater distributary channel?Subaqueous levee?Mouth bar?Distal bar?Sand sheet?Lower nearshore and Middle shoreface.The division of sequence include of Three System domains:lowstand system tract(LST)?highstand system tract(HST)?transgressive systems tract(TST).Analysising grain size?mineralogical and element geochemical characteristics of QK2 core,showed hole formation should belong to the coastal shallow water,hot dry,the weak oxidation of depositional environment. |
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